BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive debilitating lung disease with considerable morbidity. Heterogeneity in epidemiologic studies means the full impact of the disease is unclear. METHODS: A targeted literature search for population-based, observational studies reporting incidence and/or prevalence of IPF from January 2009 to April 2020 was conducted. Identified studies were aggregated by country. For countries with multiple publications, a weighted average was determined. Incidence and prevalence data were adjusted for between-study differences where possible. The final model included adjusted estimates of incidence and prevalence per 10,000 of the population with 95% confidence intervals. As prevalence estimates vary depending on the definitions used, estimates were based on a specific case definition of IPF. RESULTS: Overall, 22 studies covering 12 countries met the inclusion criteria, with 15 reporting incidence and 18 reporting prevalence estimates. The adjusted incidence estimates (per 10,000 of the population) ranged from 0.35 to 1.30 in Asia-Pacific countries, 0.09 to 0.49 in Europe, and 0.75 to 0.93 in North America. Unadjusted and adjusted incidence estimates were consistent. The adjusted prevalence estimates ranged from 0.57 to 4.51 in Asia-Pacific countries, 0.33 to 2.51 in Europe, and 2.40 to 2.98 in North America. South Korea had the highest incidence and prevalence estimates. When prevalence estimates were compared to country-specific rare disease thresholds, IPF met the definition of a rare disease in all countries except South Korea. There were notable geographic gaps for IPF epidemiologic data. CONCLUSIONS: Due to differences in study methodologies, there is worldwide variability in the reported incidence and prevalence of IPF. Based on the countries included in our analysis, we estimated the adjusted incidence and prevalence of IPF to be in the range of 0.09-1.30 and 0.33-4.51 per 10,000 persons, respectively. According to these prevalence estimates, IPF remains a rare disease. For consistency, future epidemiologic studies of IPF should take age, sex, smoking status, and the specificity of case definitions into consideration.
- Maher, T. M.
- Bendstrup, E.
- Dron, L.
- Langley, J.
- Smith, G.
- Khalid, J. M.
- Patel, H.
- Kreuter, M.
Keywords
- Case definition
- Epidemiology
- Idiopathic pulmonary fibrosis
- Interstitial lung disease
- Modeling
- Rare disease
- GlaxoSmithKline and UCB, and has received consultancy or speaker fees from Apellis,
- AstraZeneca, Bayer, Blade Therapeutics, Boehringer Ingelheim, Bristol Myers Squibb,
- Galapagos, GlaxoSmithKline, Indalo, Novartis, Pliant, ProMetic, Respivant, Roche,
- Samumed, and UCB outside the submitted work. EB reports grants and personal fees
- from Galapagos during the conduct of the study, and from AstraZeneca, Boehringer
- Ingelheim and Roche outside the submitted work. LD and GS are employees of Cytel,
- which received funding from Galapagos NV for the current work. JL and JMK are
- employees of and warrant holders at Galapagos NV. HP is an employee of Immensity
- Consulting, Inc. which received funding from Galapagos NV for the current work. MK
- reports grants and personal fees from Galapagos during the conduct of the study, and
- grants and personal fees from Boehringer Ingelheim and Roche outside the submitted
- work.
